Game doesn't run - error 0x8000001

Here are a few things you can try:
 
- Clear Game/Launcher Cache:
 
- EA App
- Steam
- Epic Games

Note: Steam doesn't exactly have a way to clear the game's cache, only a way to clear the download cache, but it might help.

On console, I'm not sure how to do this.  

- Repair your system's files:

- Open the Command Prompt in administrator mode

- Type, "DISM /Online /Cleanup-image /Restorehealth" (without the quotes), and wait for it to finish.

Note: DISM stands for "Deployment Image Servicing and Management tool". It often repairs Microsoft related files, such as issues with Window apps. Some problems with the next file checker can only be fixed after running this one first.

- Now type, "sfc /scannow" (without the quotes), and wait for it to finish.

Note: sfc stands for "System File Checker". This one will repair system files, (such as important Windows drivers).

- Lastly, restart your PC.

On Linux, some had reported that updating their system had fixed the issue for them. Check with the OS' support page on how to repair the system's files.

On console, I'm not sure how to do this. Check in your console's system settings.
 
- Changing your graphics settings in the system settings:

- Windows Settings > System > Display > Graphics > Change Apex Legends' graphics.

- For Linux, check how to do this on their OS support page.

- For console, I don't think this is an option.
 
- Other possible fixes for PC players:

- Disabling any programs that may interfere with Apex Legends.

- If you use AMD Software꞉ Adrenalin, try reinstalling it.

Lastly, when it comes down to the EAC, I personally wouldn't mess with it.